subject arboricultural assessment orewa coastal...

Orewa Sea Wall – Oct 16 – [22436] of 17

To

Tonkin and Taylor Level 2, 105 Carlton Gore Road Newmarket, Auckland 1031

Prepared by Reviewed by

Peter van Loon Leon Saxon

Attention

Sarah McCarter Ian Murray

Date Ref

14th December 2016 22436

Subject

- Arboricultural assessment - Orewa Coastal Walkway and Seawall, Orewa

1. Introduction

1.1. Arborlab Consultancy Services Ltd has been engaged to undertake an arboricultural

assessment of a proposal to carry out an upgrade to the existing seawall at Orewa Beach,

Orewa.

1.2. The findings and recommendations contained herein are based on the information captured

during a site survey undertaken on 17th March 2016 as well as the following documents and

communications.

Site meeting with Tonkin and Taylor planner Sarah McCarter and Auckland Council Project Manager Ian Murray (17th March 2016)

Site meeting with Tonkin and Taylor engineer Tim Allsopp-Smith, Auckland Council Project Manager Ian Murray, Auckland Council Heritage Arborist Nick Stott, Auckland Council Landscape and Arboricultural Advisor Ben Free (20th September 2016).

2. Attachments

2.1. Photoset 2.2. Arborlab Drawings PVL-22436-01[A] to PVL-22436-03[A] 2.3. Heritage Arborist Comments – Mr. Nick Stott 2.4. Asset Owner Approval – Mr. Ben Free

3. Zoning

Auckland Unitary Plan – Operative in Part

3.1. Road Reserve

3.2. Open Space – Conservation Zone

3.3. Open Space – Informal Recreation


4. Tree protection status

4.1. The following rules of the Auckland Unitary Plan (Operative in Part) apply.

Activity Table E26.4.3.1 – Network utilities and electricity generation – Trees in roads and

open space zones and the Notable Trees Overlay

(A83) – Tree trimming or alteration (that complies with standards E26.4.5.1) - Permitted

(A87) – Works within the protected root zone that comply with Standard E26.4.5.2 – Permitted

(A88) – Works within the protected root zone not otherwise provided for – Restricted Discretionary

(A92) – Tree alteration or removal of greater than 4m in height and trees 400mm in girth – Restricted

Discretionary

4.2. Overall the activity status of the proposal, from a vegetation perspective, is Restricted

Discretionary.

5. Site details

5.1. The subject site is a section of Orewa Beach between Marine View and Kohu Street. There is

an existing seawall which separates the beach from a grassed area which is elevated above

the beach.

5.2. Specifically in relation to the area which this proposal affects; this is a section of the seawall

and adjacent grassed area approximately 600 metres in length. Figure 1 on the following page

depicts the site location.


Figure 1: Site location

6. The proposal

6.1. The proposal is to construct a new sea wall at the northern end of Orewa Beach, between

Kohu Street and Marine View. The location of the new sea wall will allow for the construction

of a formal concrete pedestrian path above the sea wall.

6.2. From a vegetation alteration perspective, the proposal requires the removal of two protected

trees within Kinloch Reserve, and works within the root zone of a further 17 protected trees.

Eight of these trees are listed in the Notable trees appendix. In addition, some minor pruning

of trees 3 and 4 may be required for reconstruction of the pedestrian bridge in Kinloch reserve.

7. Main findings

7.1. An inventory of the potentially affected trees is included in Table 1 on the following page. Each

tree has been assigned a number which corresponds to the numbered tree plots depicted on

drawings PVL-22436-01 – PVL-22436-03, included as Appendix 2.


Table 1: Tree inventory

* CSR – Crown Spread Radius. The greatest distance from the edge of the main stem, to the furthest distal branch tip.

* CRR – Critical Root Radius – Adapted from Coder (1996) – The radial distance from the stem of the tree within which the main structural root plate is contained

* TPR – Tree Protection Radius – Derived from Harris et al (2004). The radial distance from the trunk of the tree at which isolation fencing should be placed to adequately protected root zones from damage.

Tree # Botanical name Common nameHeight

(m)

Aggregate

girth at

1.4m (mm)

CSR

(m)Form Structure Health Age class

Protection

statusOwnership Proposal

CRR

(m)

TPR

(m)

1 Araucaria heterophylla Norfolk Island pine 30 4950 6 Good Fair Good Mature Scheduled Reserve Retain 4.4 14.2

2 Metrosideros excelsa Pohutukawa 8 3000 5 Fair Fair Good Mature Protected Private Retain 3.3 8.6

3 Metrosideros excelsa Pohutukawa 7 1000 4 Fair Fair Good Semi-mature Protected Private Retain 1.8 2.9

4 Pittosporum crassifolium Karo 6 800 4 Fair Fair Good Semi-mature Protected Reserve Retain 1.6 2.3

5 Metrosideros kermadecensis Kermadec pohutukawa 4 700 4 Poor Fair Fair Juvenile Protected Reserve Remove 1.5 1.5

6 Metrosideros kermadecensis Kermadec pohutukawa 4 650 4 Fair Fair Fair Juvenile Protected Reserve Remove 1.4 1.4

7 Araucaria heterophylla Norfolk Island pine 16 2000 6 Good Fair Good Semi-mature Scheduled Private Retain 2.7 5.7

8 Metrosideros excelsa Pohutukawa 8 3000 5 Fair Fair Good Mature Scheduled Private Retain 3.3 8.6




12 Araucaria heterophylla Norfolk Island pine 16 4100 6 Good Fair Good Semi-mature Scheduled Joint Retain 4.0 11.7

13 Metrosideros excelsa Pohutukawa 8 3210 5 Fair Fair Good Semi-mature Protected Reserve Retain 2.4 4.7

14 Metrosideros excelsa Pohutukawa 3 490 2 Poor Fair Poor Juvenile Protected Reserve Retain 1.0 1.0


16 Araucaria heterophylla Norfolk Island pine 25 3900 8 Fair Fair Good Mature Protected Reserve Retain 3.9 11.2


18 Araucaria heterophylla Norfolk Island pine 25 3760 8 Fair Fair Good Mature Protected Reserve Retain 3.8 10.8

19 Metrosideros excelsa Pohutukawa 10 8350 6 Fair Fair Good Mature Scheduled Reserve Retain 3.3 8.6


8. Arborist comments

8.1. The concrete path is to be constructed on-grade. In some areas, fill may be required to build

up the level required for the path. No excavation, beyond the removal of the grass layer, is

anticipated for the construction of the concrete path. The path construction is to incorporate a

load distributing system, such as geo-web, in the areas where the path crosses the root zone

of a tree.

8.2. An existing concrete driveway is located at the Marine View beach entrance, where an

easement through council land is in place to provide vehicle access to the rear of 331 Hibiscus

Coast Highway. This concrete driveway will form a part of the new footpath, with the existing

driveway surface to be removed and replaced. No excavation beyond removal of the concrete

surface and basecourse is to occur, so as to not disturb or damage any roots beneath the

existing driveway.

8.3. Two trees are proposed to be removed – trees 5 and 6, located within Kinloch Reserve. The

removal of these trees in necessitated by the construction of the path, and the earthworks

required in achieving the required levels.

8.4. The construction of the new sea wall is within the root zones of trees 13, 14, 15 and 17. Roots

from these trees are visibly protruding from the existing bank face. Care must be undertaken

when constructing this segment of the sea wall, that rock placement does not damage any tree

roots. The placement of the rock wall surrounding trees 13, 14, 15 and 17 should be

undertaken with care, and in conjunction with arboricultural supervision. Roots should be

protected from damage prior to placement of rocks by wrapping exposed roots with a suitable

protective material, such as hessian cloth.

9. Conclusions

9.1. Providing the rock wall is installed carefully when within the protected root zones of trees on

site, and the path incorporates a load distributing mechanism (geo-web) in “sensitive”

locations, it is expected that the project may proceed without any detriment to the trees’ health

and longevity.

10. Recommendations

10.1. A suitably qualified and experienced council approved arborist (works arborist) shall be

engaged by the consent holder at the start of the project to supervise all works in the vicinity of

the trees. The appointed works arborist must be experienced in tree protection systems and

construction methodologies, and will need to be able to coordinate site works ensuring that the

tree protection methodology is correctly implemented.

10.2. In the first planting season following completion of works, two new trees of a minimum 45L

grade shall be planted within Kinloch Reserve, to the satisfaction of the Landscape and

Arboricultural Advisor.

10.3. The load distributing system used beneath the footpath in the areas where it is necessary to

do so (for example where roots are present), should consist of a cellular confinement system

such as geo-web filled with a no-fines GAP20 aggregate which is lightly compacted by hand

prior to pouring concrete. This will need to be laid on grade i.e. without excavation. Where the


existing ground contours need to be levelled, sand, topsoil or other appropriate material should

be used to “build up” areas which require modification. Note: this recommendation is subject to

engineering approval.

10.4. In areas where it is deemed necessary to do so by the supervising works arborist, a layer of

geo-textile fabric shall be laid over any exposed roots which will have fill material emplaced on

top.

10.5. The following tree protection methodology should be adhered to at all times.

9. Tree protection summary

Site pre-commencement meeting held and documented.

Works arborist to direct the erection of the protective fencing as required prior to

commencement of works.

Ground protection measures to be emplaced before tracking or manoeuvring

vehicles/machinery over root zones

Adherence to control methods as specified in the conditions of consent.

Works arborist on site to supervise any works in the vicinity of the root zone of any of the trees.

Arboricultural end of project report compiled and submitted if required or requested.

The following reporting shall be adhered to at all times.

10. Reporting

Item Reporting

Pre-commencement meeting Pre-commencement minutes

Tree protection in place

Memo if required or requested Excavations adjacent to trees

Confirmation of root pruning

Monthly inspection

Final inspection Final report upon completion

11. Tree protection methodology

11.1. Prior to works commencing, the consent holder shall arrange a pre-start meeting with the site

foreman, contractor, and the appointed works arborist. An invitation to the meeting shall be

given to Council’s Representative with at least five working days’ notice. At the meeting, the

foreman shall agree with the works arborist:

The methodology and timing of the works

Site access and areas for manoeuvring vehicles and machinery

Areas for storing and/or stockpiling materials, spoil and equipment

The care needed when working around trees

The conditions of the resource consent


11.2. At the completion of works, the works arborist at his or her discretion shall “sign off” the work of

the contractor, and if requested, provide a brief account of the project to the council arborist (if

necessary with photos). The account of works shall include, but not be limited to:

The effects of the works to the subject trees

Any remedial work which may be necessary

11.3. It shall be the consent holder’s responsibility to ensure that all persons engaged or otherwise to

work on the site are made aware of the conditions of consent, and that those conditions are

adhered to at all times.

11.4. No work shall take place within the root zone and/or drip line of the trees without prior approval

from the works arborist. Any amendments to the tree protection methodology shall require prior

written approval from the works arborist, written confirmation of which shall be forwarded to

Council.

11.5. Prior to works commencing, a suitable protective fence shall be erected around the trees. The

exact location and nature of the protective fence shall first be agreed upon with the works

arborist. For the duration of time the protective fence is in place, the area enclosed by the fence

shall be regarded as sacrosanct, and no material is to be stored, emptied or disposed of within

the area enclosed by the protective fence. No person, vehicle or machinery may enter the area

enclosed by the protective fence unless otherwise authorised to do so by the works arborist.

11.6. If for any reason it becomes necessary to move the protective fencing, then for the duration of

time that the protective fence is not in place, the area which was previously enclosed by the

fence shall be regarded in the same manner as if the protective fence were still in place.

11.7. No material is to be stored, emptied or disposed of in or around the root zone of any of the trees

unless otherwise authorised to do so by the works arborist. Any material which is to be stored or

temporarily placed in or around the root zone of any of the trees shall be stored carefully on an

existing or temporary hard surface such as asphalt or plywood sheets respectively.

11.8. If during the course of the works, machinery or vehicle access/manoeuvring is required in or

around the root zone of any of the trees, then depending on the nature of the loading of the

machinery or vehicle, it may be necessary to cover those areas with a protective overlay

sufficient to protect the ground from being muddied, compacted, churned up or otherwise

disturbed (for example “Track Mats”, or a layer of mulch or sand/SAP7 overlaid if necessary with

a raft of wire planks, plywood or similar).

11.9. If machinery/vehicles are to be operated or stored within the root zone area on an existing or

temporary load bearing surface, then the machinery/vehicle shall not cause any detrimental

effect to the tree(s) through compaction, physical damage, spillage of lubricants and fuels or

discharge of waste emissions.

11.10. All excavations which are to take place in or around the root zone of any of the trees shall be

done so in conjunction with the works arborist, through a careful combination of machine

excavation and hand digging, and to the satisfaction of the works arborist.

11.11. Any roots which are encountered during any part of the process are to be retained where

possible. Every effort shall be made to retain all roots 30mm in diameter or greater. The

severance of any root less than 30mm shall be done so at the discretion of the works arborist.

Where roots are to be severed, they shall be cut cleanly by the works arborist with a sharp hand

saw or loppers, and the area around the root shall be backfilled with the original material.


11.12. When a root greater than 30mm in diameter is impeding the construction and all other

alternatives to work around the root have been exhausted, the supervising works arborist shall

only remove the root if he/she determines that it shall not have a detrimental effect on the health

and stability of the tree.

11.13. Where roots to be retained are encountered and there is need for these roots to remain exposed

in order that works are not impeded, then those roots shall be covered with a suitable protective

material (such as moist Hessian, or a wool mulch) in order to protect them from desiccation

and/or mechanical damage, until such a time as the area around the root can be back filled with

the original material. The wrapping or covering of any roots shall be undertaken by the works

arborist.

11.14. The cutting, breaking and lifting of any concrete and/or asphalt around the root zone of any of

the trees shall be done so in conjunction with the works arborist through a careful combination

of machine and hand operated equipment. Ideally, the concrete/asphalt will first be cracked or

broken with a steel bar or sledge hammer, and the sections of concrete carefully lifted out by

hand. At the discretion of the works arborist, the cutting, cracking, lifting and removal of

concrete/asphalt may proceed with machinery, such as a concrete cutter, and/or small

excavator. All excavators and machinery shall sit on the existing concrete/asphalt surface and

work slowly backwards away from the trees.

11.15. If during the works, there are large areas of root zones exposed, then it may be necessary to

protect the exposed root zone with a protective overlay sufficient enough to protect the ground

and roots from being disturbed, for example a layer of geotextile fabric laid over a 150mm thick

layer of wood mulch.

11.16. Where concrete is to be poured into excavations containing exposed roots, then all exposed

roots shall first be covered in a layer of polythene to prevent the concrete from contacting the

exposed root.

11.17. If during the works it becomes necessary to pour concrete and/or lay asphalt directly over

exposed roots, then all exposed roots shall first be covered with a layer of fine sand not less

than 75mm thick and a layer geotextile fabric shall be placed over the roots prior to pouring the

concrete/asphalt.


Appendix 1: Photoset

Photo 1: Location of proposed path.

Photo 2: Location of proposed path.

15

16

9 8


Photo 3: Trees 5 and 6 – to be removed.

Photo 4: Existing driveway easement and tree 18.

5 6


Appendix 2: Drawings PVL-22436-01[A] to PVL-22436-03[A]

Orewa Beach Sea WallOrewa

PVL/LGSPVLLGS

17/03/1611/08/16

PVL-22436-01 A

03/10/16

N N

TREE LOCATION PLAN


PVL/LGSPVLLGS

17/03/1611/08/16

PVL-22436-02 A

03/10/16

N N

TREE LOCATION PLAN


PVL/LGSPVLLGS

17/03/1611/08/16

PVL-22436-03 A

03/10/16

N N

TREE LOCATION PLAN


Appendix 3: Heritage Arborist Comments – Mr. Nick Stott From: Nick Stott [mailto:[email protected]] Sent: Wednesday, 12 October 2016 4:09 p.m.

To: Peter van Loon; Benedict Free

Cc: Heritage Consents Subject: RE: North Orewa Beach Sea Wall

Hi Peter, Having walked the route and now having read through your report, I am happy with the proposed recommendations and the load distribution methodology when within the root zone of scheduled trees. Please take this email as my support for you to lodge for consent. If there is anything else you require from me at this stage, please advise. Thanks Nick,

Nick Stott| Heritage Arborist Heritage Plans and Places Chief Planning Office Auckland Council Mobile 021814729 Auckland Council, Level 23, 135 Albert St

Visit our website: www.aucklandcouncil.govt.nz

http://www.aucklandcouncil.govt.nz/

Auckland Council Asset Owner approval – Trees

Please complete as much of the form as possible. Please complete all shaded areas

Please return to Arboriculture Advisor, Environment and Programmes

Level 3 The Strand, Takapuna, Auckland

E-mail [email protected]

Information required – Site plan A1 or A3 showing the location of the council owned tree, arborist report if one has been commissioned, drainage plans, utility plans, consent number etc. Date: 12/10/2016 Pruning works □ Tree Removal □

Excavation work in the dripline □

Site address:

North Orewa Beach, Orewa

Official Use only Plans supplied: Yes / No Plan No. Consent application √ Application No.: Vehicle crossing □ Arborist report: Yes √ / No □ Utility application □ Tree species: Various House mover □ Asset ID No.: Building consent □ Resource Consent: yes Private connection utility □ Asset owner approval required

yes Infrastructure works 1. new work

2. upgrade

3. emergency

□ □ □

Proposal – scope of works – please describe the proposed work

See attached report by Peter van Loon – Orewa Sea Wall – Oct 16 [22436]

√ √

√

Official use only To be filled in by council arborist advisor Asset owner approval is granted subject to the following requirements:

1. All works shall be carried out in accordance with Arborlab Arboricultural Report, prepared by Peter van Loon titled ‘Arboricultural Assessment Orewa Sea Wall, Orewa’ dated October 2016. Provided they are consistent with the following conditions: 2. All tree removal, pruning and replacement planting shall be carried by council’s contractor Treescape at the consent holders’ expense. Other contractors are permitted provided they are on Auckland Council’s Health and Safety Register. 3. Replacement planting shall be undertaken within the next annual planting season (May – September) immediately following tree removal. Consultation on replacement planting shall be carried out by the applicant. All replacement planting shall be approved by Council’s Parks Arborist. 4. The applicant shall undertake a two year maintenance period which must include watering and general maintenance of staking and mulch.

Please note asset owner approval does not allow you to proceed until you have all of the relevant consent approvals required for your project. A copy of this form should be held on site at all times.

I agree to the requirements set out by the Auckland Council asset owner

Agent: Name Peter van Loon - Arborlab Signature Date 12/10/16___

Address: 76D Paul Matthews Road, Rosedale____________________________________

Contact details: _________________________________________________________________

Auckland Council

Environment and Programmes

Arboriculture Advisor

Benedict Free

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